package com.knowif.util.commonUtil;

import javax.crypto.Cipher;
import javax.crypto.spec.SecretKeySpec;
import java.security.MessageDigest;
import java.util.Base64;

public class SecurityUtil {
    public static String stringToMD5(String s) {
        char hexDigits[] = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' };
        try {
            byte[] btInput = s.getBytes();
            MessageDigest mdInst = MessageDigest.getInstance("MD5");
            mdInst.update(btInput);
            byte[] md = mdInst.digest();
            int j = md.length;
            char str[] = new char[j * 2];
            int k = 0;
            for (int i = 0; i < j; i++) {
                byte byte0 = md[i];
                str[k++] = hexDigits[byte0 >>> 4 & 0xf];
                str[k++] = hexDigits[byte0 & 0xf];
            }
            return new String(str);
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }
    public static byte[] decode(String encodedText){
        final Base64.Decoder decoder = Base64.getDecoder();
        return decoder.decode(encodedText);
    }

    public static String decryptData(String base64Data,SecretKeySpec key) throws Exception {
        Cipher cipher = Cipher.getInstance("AES/ECB/PKCS5Padding");
        cipher.init(Cipher.DECRYPT_MODE, key);
        return new String(cipher.doFinal(decode(base64Data)));
    }






}
